Heavy equipment including, but not limited to, earth moving equipment, construction equipment and vehicles, large off-road trucks and vehicles, surface mining equipment and vehicles, mineral and earth processing equipment and other equipment used in quarries and mines, and other vehicles and large sized equipment frequently used in off road applications and not suitable for use on existing roadways often employ very large, very heavy mirrors that are used by operators when operating the vehicles or equipment. These mirrors are typically located at a distance from the operator's seat or position that places them beyond reach when the operator is in the operator position. Accordingly, it is not possible for the operator to manually adjust the mirror to the proper angle from the location where the operator is positioned when the equipment is being operated.
Given the size of the equipment and the distance between the operator position and the mirror, mirror adjustment is either a two person task or, in a one person adjustment procedure, mirror adjustment requires the operator to leave the operating position, move to and adjust the angle/position of the mirror, return to the operator position to check whether the adjustment was appropriate and repeat as necessary until the adjustment is completed. Failure to have properly adjusted mirrors can results in inefficiencies and performance errors by the operating including the possibility of unsafe and/or inefficient operation including the potential for catastrophic accidents.
Remote controlled mirrors that are typically used in passenger and small off road vehicles are unsuitable for use in large heavy vehicles and equipment used in off road applications. The challenges presented by the size of the mirrors, by the conditions that occur when the large heavy vehicles and equipment is in operation, and the environment in which the large heavy vehicles and equipment is typically used, render small vehicle remote control mirror designs inadequate.
The mirrors used in large heavy vehicle and equipment applications are very heavy and the weight of the mirrors presents a significant challenge to designing remote controlled mirror system. Weights in excess of 10-25 pounds for mirrors used on heavy equipment are not uncommon with some being up to 80 pounds and some up to 125 pounds or more. Supporting and precisely moving and stopping movement of such large, heavy mirrors pose difficulties and problems not present when designing mirrors to be used in road-able vehicles. Being able to move and “precisely” stop mirrors weighing in excess of 10 pounds, in excess of 20 pounds, in excess of 50 pounds, in excess of 80 pounds, in excess of 100 pounds or in excess of 125 pounds is extremely difficult. The exterior-mounted rearview/sideview mirrors used in road-able vehicles such as cars, semi-tractors, RV's, are relatively small and weigh only a few pounds, typically 2-10 pounds. Typical passenger vehicle mirror designs employed in remote controlled mirror for these smaller applications are unsuitable because they are not designed to operate with such large heavy mirrors and the loads that are associated with supporting and remotely moving such mirrors. Due to the extra weight of the mirrors used in heavy equipment applications, simply increasing the size of passenger remote control mirror designs is impractical when taking into account the need to use the remote control mirror in place of existing manually adjustable mirrors. The heavy weight of the mirrors causes significant problems in designing remote controlled mirrors, especially because it is desirable to minimize difference in weight between remote controlled mirrors and manually adjusted mirrors, the weight is capable of being supported by structures present on existing equipment. It is also not feasible to do so in many instances because the heavy equipment is not simply a large version of passenger vehicle. Heavy equipment creates conditions that effect and create problems for remote controlled mirrors that are not comparable to passenger vehicle applications. Moreover, the environment and conditions in which heavy vehicles are used create problems and design challenges that don't exist or are not addressed in comparable to passenger vehicle applications.
The several specific factors to be considered in design of remote controlled mirrors for heavy equipment include harmonic vibration, loads arising from shock forces, high likelihood of impacts with debris, high levels of air borne particulates and extreme temperatures. Problems are encountered in the off road use of large heavy equipment include the challenges caused by the mirror vibration due to the type and level of vibration caused by engines used in heavy equipment. The overall system needs to be able to withstand the harmonic frequency's being introduced via the equipment. Remote controlled mirrors used in heavy equipment must be robust enough to withstand the static and dynamic forces of an off road environment and protect both the mirrors surface and the operating systems ability to function and remain in operational condition over a lifetime comparable to that of a manually adjusted mirror. Additionally, mirrors used in heavy equipment are often repeatedly struck by falling and flying stones and rocks and must be designed to withstand such occurrences and continue to operate and function properly. Moreover, dusty and dirty conditions with high levels of particulates in the atmosphere are common in locations where heavy vehicles and equipment are used and mirror designs must ensure that such conditions do not interfere with continued proper operation or cause premature breakdown or malfunctioning. Further, heavy equipment is often deployed and regularly operated in locations that experience extreme weather conditions. Remote controlled mirrors used in heavy equipment can be subjected to extreme temperatures.
Vibration in heavy vehicles and equipment causes problems not experienced using small mirrors such as those used in in passenger and small off road vehicles. The engines used to power large heavy vehicles and equipment create vibration that greatly exceeds the vibration produced by smaller vehicles. The distance between mirror and operator position is significantly greater than distances in small vehicle application. The need for a mirror's reflective surface to remain motionless (not vibrate) while the heavy vehicle of equipment is moving or idling is among the most important aspects of mirror design for heavy equipment. The reflected image from a slightly vibrating reflective surface is distorted. In addition, the vibration makes it very difficult for the operator to properly focus his/hers eyes on the image. The vibration caused by such large engines must be addressed and mitigated in the design of remote controlled mirrors for heavy equipment to ensure that the mirror function properly when the engine is running. The mirrors designs used in these applications must not only meet the unusually large size and weight requirements but also remain functional when the common amount of vibration associated with this type of equipment is present. Passenger car mirrors are not designed to function in conditions having vibration typical in heavy equipment use.
Moreover, when such heavy equipment is in use and/or motion, shock forces can occur which further cause movement and additional load on weight bearing structures attached to such equipment. Mirror designs must be of sufficient strength to withstand the additional loads on components and shock forces that are common cannot cause operational failure and/or damage to the remote controlled mirror or components therein. The remote controlled mirror design and the components used must be able to continue to operate following exposure to g-forces of +5 g or that are produced by the additional load which commonly results from shocks that occur in the ordinary usage of the heavy equipment. Given the heavy weight of the mirrors, the additional loads routinely produced by shock forces create the need for a design which can not only withstand the large force created but which can repeatedly withstand such forces and remain in service. Remote controlled mirrors designed for use in passenger cars and small off-road vehicles do not address the potential problems that occur due to the increased load caused by shock forces.
The amount of debris which routinely falls or is thrown about the heavy equipment tossed is quite high relative to that commonly encountered by passenger vehicles given that the heavy equipment is typically used in excavation, mining and construction sites. The remote controlled mirror is expected to be durable under such conditions.
Further, the environment in which heavy equipment are deployed, such as excavation, mining and construction sites, have large amounts of dust, dirt, particulates and other environmental factors that require a more robust design that simply a large scale version of a passenger mirror design affords.
It is not uncommon for heavy equipment to be used in arctic and near-arctic conditions as well as in desert conditions. The design must be able to remain operational at extreme temperatures and withstand the various forces, impacts and environmental conditions at such temperatures.
There is a need for a remote controlled mirror for use in heavy equipment which can be adjusted by the operator from the operator position, which has a mirror that is large enough to be effective when used with heavy equipment, and which can function adequately under the vibration and environmental conditions and shock forces common in the off road applications of such equipment.